Tonya Illman, who found the bottle on January 21, said: “It just looked like a lovely old bottle so I picked it up thinking it might look good in my bookcase.

“My son’s girlfriend was the one who discovered the note when she went to tip the sand out. The note was damp, rolled tightly and wrapped with string.

“We took it home and dried it out, and when we opened it we saw it was a printed form, in German, with very faint German handwriting on it.”

The Meterological Journal from the Paula (KymIllman.com)

Mrs Illman and her husband Kym researched the find and discovered that the German Naval Observatory – Deutsche Seewarte – threw thousands of bottles into the ocean containing the date it was cast into the water, the ship’s co-ordinates and its destination.

The letters asked the finder to write when and where the bottle was found as part of an experiment.

Initial investigations by the Western Australian Museum established that the bottle was a mid to late 19th century Dutch gin bottle, the paper and colouration were consistent with cheaply-made 19th century paper, and the German bark Paula sailed from Cardiff to Makassar in 1886.

The finder was asked to write to the Deutsche Seewarte with details about where they discovered the message (KymIllman.com)

“Extraordinary finds need extraordinary evidence to support them, so we contacted colleagues in the Netherlands and Germany for help to find more information,” said Dr Ross Anderson, assistant curator maritime archaeology at the museum.

“Incredibly, an archival search in Germany found Paula’s original Meteorological Journal and there was an entry for 12 June 1886 made by the captain, recording a drift bottle having been thrown overboard. The date and the co-ordinates correspond exactly with those on the bottle message.”

The find has been determined to be authentic by the German Federal Maritime and Hydrographic Agency (BSH).

A report from the BSH said: “The knowledge about the ejection of a bottle post with exactly this data about ship, route and exact date would be available only through the access to various historical sources. However, these sources are not easily accessible to the public. This makes a fake in terms of content extremely unlikely.”

The bottle has been loaned to the Western Australia Museum in Fremantle by Mr and Mrs Illman, and will be on display for the next two years.